The heavy ion cyclotron U-400 in Dubna, where ununoctium may have been synthesized.

Discovery of Ununoctium

Dr. Doug Stewart

Research scientists at the Joint Institute for Nuclear Research in Dubna, Russia and the Lawrence Livermore National Laboratory (LLNL), California believed they had made element 118, ununoctium, in 2002.

Calcium ions were formed into a beam in a cyclotron (a particle accelerator) and fired at a target layer of californium oxide deposited on titanium foil.

Bombardment lasted 2300 hours, accumulating a total dose of 2.5 x 1019 calcium ions.
Two atoms of ununoctium-294, which existed for 2.55 ms and 3.16 ms, may have been produced in March 2002. (1)

In 2011, The International Union of Pure and Applied Chemistry (IUPAC) reviewed the work done in Dubna and at the LLNL, and did not accept that there was enough evidence to accept ununoctium as an established element.

The report stated, “the three events reported for the Z = 118 isotope have very good internal redundancy but with no anchor to known nuclei do not satisfy the criteria for discovery.” (2)

As a result of its position in the periodic table ununoctium is expected to be classed as a noble gas.

Too little of the element has been synthesized for this to be confirmed, although some calculations indicate ununoctium might in fact be solid at room temperature.

The joint teams at JINR in Dubna and Lawrence Livermore in California have published evidence for the synthesis of elements 113, 114, 115, 116, 117 and 118.

Appearance and Characteristics

Ununoctium is a synthetic radioactive metal and has only been produced in minute amounts.

Uses of Ununoctium

Ununoctium is of research interest only.

Abundance and Isotopes

Abundance earth’s crust: nil

Abundance solar system: parts per trillion by weight, parts per trillion by moles

Cost, pure: $ per 100g

Cost, bulk: $ per 100g

Source: A few atoms ununoctium may have been created via nuclear bombardment of 249Cf with 48Ca ions in a heavy ion accelerator. IUPAC does not accept there is enough evidence to accept ununoctium as an established element.

Isotopes: Ununoctium may have one isotope whose half-life is known very approximately: 294Uuo, with a half-life of 0.89 milliseconds.